共址天线干扰抵消系统的调幅制干扰抵消特性

Cancellation performance of co-site antenna interference cancellation system for AM interference

分析了调幅制干扰信号下,实际共址天线干扰抵消系统的干扰抵消性能。给出调幅制(AM, amplitude modulation)信号下干扰抵消系统稳态权值表达及其结构特性,推导出载频和边频干扰抵消比的计算式,分析得到干扰抵消比的影响因素及其影响规律。干扰抵消系统的稳态权值为载频和边频最优权值按功率比的加权,信号带宽增大将增大载频和边频最优权值的离散性,从而导致干扰抵消比的下降。边频干扰抵消比比载频干扰抵消比随信号带宽增大而下降的程度更加明显,通过提高系统增益来提高系统干扰抵消比的程度有限。给出干扰抵消比极限与等效传输延时之间的关系,提出干扰抵消系统在调幅制AM信号下提高干扰抵消比的设计方法。仿真结果验证了理论分析的正确性和有效性。

The interference cancellation performance of actual co-site antenna interference cancellation system(CICS)under amplitude modulation jamming signal was analyzed.The expressions of the steady-state weights and theirs structure characteristics of the interference cancellation system under the AM signal were given.The formulae of the interference cancellation ratio(ICR)for carrier frequency and side frequency were derived.The influence factors and the influence rules of the ICR were analyzed.The steady state weights of the interference cancellation system(ICS)were the weighting of the carrier frequency optimal weights and the edge frequency optimal weights according to the power ratio.The increase of the signal bandwidth will increase the discreteness of the carrier frequency optimal weights and the edge frequency optimal weights and lead to the decrease of the interference cancellation ratio(ICR).The decrease degree of the edge frequency ICR was greater than that of the carrier frequency ICR.To improve ICR by increasing the gain was limited.The relationship between the interference cancellation ratio limit and the equivalent transmission delay was given.The design method of the interference cancellation system to improve the ICR under the AM signal was proposed.Finally,the correctness and validity of the theoretical analysis was verified by simulation.